When I try to save an Illustrator file as a PDF that I've saved before, Illustrator asks me if I'd like to replace my old file with the new one I'm saving (which is normal). I click okay, and everything looks normal about the save, but Illustrator doesn't actually save over the old file with my new changes, unless I change the name of the file. This seems like a bug. If I ask it to replace my old file upon saving, I really would like it if it did.